Pros:

Fantastic design - Looks like the "real" exterior for the mall.

Story - Love the idea.  Ties into L4D all the way.

Great Areas - Love how each area is unique and provides a different feel to the map

Good spread of weapons - In both Scavenge and Survival, the random weapons add replay value

Custom Models - Nice Touch :D Love the "Shears Auto Center"

Infected Positions - Awesome places for infected to spawn.  The roof just gives so many options!

Scavenge Mode - Each weapon and gas can seemed to have a place.  It felt like part of the map had a purpose, kudos.

Cons:

Interiors - Wish there could be more interiors, though both the clinic and the auto shop are very cool.

Fountain - The tank wasn't able to reach me in Survival, though I was at the very very top of the fountain.  The common were able to get me though.

Conclusion:

Overall, great map.  How long did you take to do this?  Seems like a long time, but great work.  All the cons I got are basically things I would like to see added, if you can.  But great work, regardless!  Love to see what else you got in the future!